[llvm] [Mips] Add r5900 (PlayStation 2 Emotion Engine) FPU Support (PR #178942)

[Matt Arsenault via llvm-commits]

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@@ -996,6 +1003,11 @@ def : MipsPat<(f32 (any_sint_to_fp GPR32Opnd:$src)),
 let Predicates = [IsR5900] in {
   def : MipsPat<(MipsTruncIntFP FGR32Opnd:$src),
                 (CVT_W_S FGR32Opnd:$src)>, ISA_MIPS1;
+  def : Pat<(f32 (MipsR5900FAdd  FGR32Opnd:$fs, FGR32Opnd:$ft)), (FADD_S $fs, $ft)>;
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arsenm wrote:

I think you could get away without these and rely on the generic node plus flags. Though maybe there's some risk of selection failure from losing flags 

https://github.com/llvm/llvm-project/pull/178942